1. Field of the Invention
The present invention relates to an apparatus and method for surface treatment of materials using intense direct irradiation from individually controllable high power laser diodes. More particularly, the present invention provides a laser diode array with fiber optic termination and a method enabling alteration of material properties near the surface or through the entire body of a material in a target region.
2. Description of the Related Art
Industrial applications of lasers involve exposing material surfaces to cause material property changes or modifications. These include applications such as hardening of metals, laser annealing, or gas immersion doping.
Conventionally, an incident laser beam impinges on only a tiny part of a surface for treatment, for example a wafer, on an incident side at any moment in time. Conventionally, this results in substantial localized thermal gradients. Additionally, conventional laser beam treatments require substantial power, which impacts process economics and efficiencies.
Temporary and rapid heating of a material may occur in air, vacuum, various gaseous environments or involve surface coatings with a variety of materials prior to high intensity radiant exposure to light produced by lasers. Exposure can result in material property changes due to re-crystallization, or different hardness or different electrical properties after such exposure. In general this involves the rapid heating and cooling of the material, and may also involve melting. For example, during the heating and cooling of the material certain molecular or atomic species contained in the ambient gas may be incorporated into the material by diffusion or chemical reaction, resulting in physical property changes of the material such as electrical properties or surface topography.
Accordingly, there is a need for an improved system and method for surface treatment of materials using intense direct irradiation from high power laser diodes. Further, there is also a need to improve process efficiencies during material treatment with laser light.